, the Satellite Test of the Equivalence Principle
is a planned (as of 2005
) space science experiment to test the equivalence principle
of general relativity
. The experiment should be sensitive enough to distinguish Einstein's theory of gravity
from many other competing theories.
The basic configuration is that of a drag-free satellite: an outer shell around an inner test mass is used to block solar wind, atmospheric drag, the Earth's magnetic field and other effects which might disturb the motion of a freely-falling inner satellite.